For conventional valved connectors, there are those of the male/female type and the tube-bonded type. In the male/female type, a main body having a valve-seating portion in which a valve is disposed is provided with a male or a female connector portion. The tubes to be connected are provided with corresponding female or male connectors, and connection is established by coupling the male and female connector portions together. It is possible to employ various structures for coupling the two, and ordinarily it is necessary that the two can be rotated relatively to one another, as in a screw-type connection. With such a male/female connector, the member to be connected can be attached or detached as necessary. In the case of the tube-bonded type, a tube is directly bonded to a tube-shaped linking portion provided on a member for seating a valve, thereby coupling them together. Consequently, the coupling is permanent.
When using such a conventional valved connector, relative rotation is impossible at the coupling portion between connector and tube in a state in which the tube line is connected by the connector. Consequently, when the tube is twisted, the rotational torque acts on the tube, whereby obstruction of the flow path in the tube or damage to the tube may be caused.
Moreover, in the case of a male/female connector, when the tube is twisted in a state in which the tube line is connected, the screwing of the screw-joint portion may be loosened, and in some cases it even may be dislodged.
Furthermore, in the case of twisting the tube-bonded connectors, there is no loosening or dislodging of the connection, but it cannot be avoided that the flow path in the tube is obstructed or that the tube is damaged. Furthermore, in tube-bonded connectors there is the problem that it is not possible to rearrange the line, and that the setup is bothersome.